Route planning devices are well known in the field of navigational instruments. The method of route planning implemented by known prior art systems depends on the capabilities of system resources, such as processor speed and the amount and speed of memory. As increased system capability also increases system cost, the method of route planning implemented by a navigation device is a function of overall system cost.
One feature of increased system capability cost involves the amount of assistance provided at decision points. Many conventional navigational devices simply do not incorporate added assistance at decision points. Thus, as a user of such a device may often get turned around or confused in unfamiliar territory. This is complicated by the fact that the circumstances such as traffic conditions, such as highway or inner city traffic conditions, often do not allow a user to pause and carefully consider a course of action at the decision point.
Conventionally, commercial auto clubs such a AAA® provide instructions for a course of action at various decision points, but without any real time added guidance or assistance for the same. Typically, the recipient of these services is provided with a set of paper maps, some even highlighting the route. However, the individual navigating the route must repeatedly flip through and study these maps before their travel and again in route. Extra attention must be given to these maps when the traveler reaches decision points in their journey. This places the user back in a compromising position when in heavy traffic conditions, as mentioned above. Even more, without self initiated independent study, the user is not provided with any sort of advance notice or warning for when these decision points are approaching. Thus, without careful planning the user can easily miss the decision point or not afford themselves with enough advance notice to be in the right position to navigate a course through the decision point.
On line map services such as MapQuest® provide similar sets of instructions for a course of action at decision points along a route, but again without any real time added guided or assistance for the same. The users of these systems also print out paper maps which they must flip through and in a self initiated independent fashion negotiate.
Finally, some navigation devices may attempt to provide a user with navigational aids for decision points while traversing a planned route. However, these systems, particularly low cost free standing navigation systems, limit such assistance to precanned bitmaps of symbols. For example, these systems may provide a turn arrow symbol indicating a direction to take at a decision point. While precanned bitmap navigational aids may be helpful in some instances, they generally do not provide enough instructional aid to a user in unfamiliar surroundings, particularly in a congested network of thoroughfares. Moreover, these devices do not provide any added assistance to negotiate among the many courses of action which match the instruction of the precanned bitmap symbol in a crowded network of thoroughfares. In other words, a left turn arrow symbol does not assist a user to understand which of several immediately approaching left turns to take.
In summary, existing navigation devices do not provide user intuitive assistance at decision points along a route. Thus, a user of these navigational aids may frequently find themselves missing decision points altogether, or not being in a correct position to navigate a course through an upcoming decision point. As such a user who is unsure about an upcoming decision may have to halt their travel to decipher the ambiguity. Clearly, in many cases halting travel is not a viable alternative. For example, when the user is traveling on an interstate it is entirely impossible to simply stop. The alternative of pulling off on the shoulder is undesirable and can be dangerous. Pulling off on an exit is equally undesirable since doing so increases travel time and provides an added inconvenience to the user. In other instances, such as navigating downtown city streets, the traffic issues alone may prevent the user from stopping their vehicle during the recalculation process. Even if the user has the ability to safely stop their vehicle, such as when traveling in a neighborhood, the inconvenience factor is present. Moreover, when the user entirely misses the decision point the headache and frustration of navigating their route is compounded, leaving the user to further resolve how to back track and again attempt to negotiate the missed decision point.
Current prior art systems have created a spectrum of products in which the degree of navigational accuracy is dictated primarily by the cost of the system. The lower cost systems currently offer a low degree of accuracy that is often inadequate for users. Therefore, there exists a need for a navigational route planning device which is more efficient and accurate than current low cost systems, without requiring more expensive system resources. In addition, there is also a need for a navigational route planning device which provides more understandable, accurate and timely assistance for negotiating decision points along a route.